Rotor-blade



P 3, 1968 Q A. F. GILES, JR 3,399,731

ROTOR-BLADE Filed July 18, 1967 H Fi .6

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United States Patent Oflice Patented Sept. 3, 1968 3,399,731 ROTOR-BLADE Algy F. Giles, Jr., 6010 Belneath, Houston, Tex. 77033 Filed July 18, 1967, Ser. No. 654,232 1 Claim. (Cl. 170-159) ABSTRACT OF THE DISCLOSURE A rotor-blade for helicopters which imparts a smoother ride and greaterlift at low speeds with a smoother ride at high speeds also. A swept-back tip at the end of each blade. This design greatly reduces the audible sound produced at the tips of the rotor.

This invention relates to air foil rotor blades, and more particularly to a high performance, low-noise rotor.

It is therefore the main purpose of this invention to provide a rotor-blade which will have swept-back tips, the tips imparting a smoother ride and greater lift at low speeds than the prior art high performance rotor conventionally used.

Another object of this invention is to provide a rotorblade which will impart a smoother ride at high speeds as well as low speeds and will greatly reduce the audible sound produced by the rotor, the construction greatly reducing the distorted air at the top and the bottom of the rotor.

Other objects of this invention are to provide a rotorblade which is simple in design, inexpensive to manufacture, rugged in constructioin, easy to use and efiicient in operation.

These and other objects will be readily seen upon a study of the following specification taken in connection with the attached drawing wherein:

FIGURE 1 is a top plan view showing a vertical-lift aircraft showing the present invention in operative use;

FIGURE 2 is an enlarged fragmentary plan view of the invention;

FIGURE 3 is a cross-sectional view taken lines 3-3 of FIGURE 2;

FIGURE 4 is a cross-sectional view taken lines 4-4 of FIGURE 2;

FIGURE 5 is a cross-sectional view taken lines 5-5 of FIGURE 2;

FIGURE 6 is a cross-sectional view taken lines 6-6 of FIGURE 2;

FIGURE 7 is a cross-sectional view taken lines 7-7 of FIGURE 2;

FIGURE 8 is a cross-sectional view taken lines 8-8 of FIGURE 2;

FIGURE 9 is a cross-sectional view taken lines 9-9 of FIGURE 2.-

According to this invention, a rotor 10 is provided with along the along the along the along the along the along the along the swept back tips 12 having a semi-tear-drop shape crosssectional configuration as is shown in FIGURES 3 to 9 in the drawing.

In use, a helicopter equipped with rotor 10 provides a smoother ride for the occupants and produces greater lift at low speeds and the noise usually associated with the prior art types of rotors is greatly reduced with rotors of this construction as presented herein.

As shown in FIGURE 1, the rotor 10 is made up of a number of radially extending members or blades 11, mounted for rotation about a central axis, and each having an elongated main portion and an outer end tip portion which is disposed in angular relation to the main portion and extends in a direction away from the direction of rotation of the rotor.

The tip portion of each rotor member or blade is of diminishing width from the main portion toward the free end of the tip, as seen in FIGURE 2, the tip being of substantially the same width as the main portion at the root end of the tip and tapering in thickness from said root end toward the free end of the tip. The main portion and tip are disposed in a common central plane which is substantially normal to the axis of rotation of the rotor and, as shown in FIGURES 3 to 9 of the drawings each of the rotor members or blades is of symmetrical shape in crosssection throughout its length, that is, the member has substantially the same cross-sectional area above and below the common central plane of the main portion and tip portion at any location in the length of the member.

What I claim is:

1. A rotor for vertical-lift aircraft comprising a plurality of angularly spaced apart airfoil members extending radially from and mounted for rotation about a central axis, each of said members being of substantially symmetrical, tear-drop shape in cross-section throughout its length having an elongated main portion and formed at its outer end with a tip portion disposed in swept-back relation to said main portion and tapering in thickness and decreasing in width from said main portion toward the free end of the tip portion, said main portion and tip portion being disposed in a common plane located centrally in the member and substantially normal to said axis.

References Cited UNITED STATES PATENTS 1,888,056 11/1932 Verzillo et a1 -159 2,408,788 10/1946 Ludington et al. 170-135.4 2,582,559 1/1952 Pearson 170-159 X 2,613,752 10/1952 Hawkins 170-159 X 3,065,933 11/1962 Williams 170-159 X FOREIGN PATENTS 46,968 8/1936 France.

EVERETTE A. POWELL, 1a., Primary Examiner. 

